From b9dfe0bed999d23ee8838d389637dd8aef83fafa Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Fri, 9 Jan 2015 10:53:21 +0100 Subject: livepatch: handle ancient compilers with more grace We are aborting a build in case when gcc doesn't support fentry on x86_64 (regs->ip modification can't really reliably work with mcount). This however breaks allmodconfig for people with older gccs that don't support -mfentry. Turn the build-time failure into runtime failure, resulting in the whole infrastructure not being initialized if CC_USING_FENTRY is unset. Reported-by: Andrew Morton Signed-off-by: Jiri Kosina Signed-off-by: Andrew Morton Acked-by: Josh Poimboeuf --- kernel/livepatch/core.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/livepatch') diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 6f6387912da7..ce42d3b930dc 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -911,6 +911,12 @@ static int klp_init(void) { int ret; + ret = klp_check_compiler_support(); + if (ret) { + pr_info("Your compiler is too old; turning off.\n"); + return -EINVAL; + } + ret = register_module_notifier(&klp_module_nb); if (ret) return ret; -- cgit v1.2.3